Patent GB-906732-A (GB)
Title: Improvements in or relating to well pumps
Inventor: COBERLY CLARENCE JAMES
IPC: F04B47/08
Filed: 1960-04-22
Abstract: 906,732. Deep well pumps. KABE Inc. April 22, 1960, No. 14171/60. Class 102(1). [Also in Group XXIX]. A fluid-operated deep well pump assembly comprises engine and pump units axially disposed in a single pump body and a separate engine control valve unit disposed in side-byside relationship with respect to the engine and pump units so that it may be removed for maintenance without the removal of the engine and pump units. As shown schematically in Fig. 3, the engine and pump units 92 comprise a plunger 46 having upper and lower plunger elements 50, 52 reciprocable in cylinder bores, 54, 56 and interconnected by a tubular rod 58 slidable in a bore 60. Surfaces 62, 64 on the plunger constitute the engine unit, the upper surface being slightly smaller in area than the lower surface and at all times subjected to the pressure of operating fluid through a duct 108 connected to supply tubing 96 in which the valve unit 94 is disposed. Alternatively the surface 64 may be constantly exposed to return tubing pressure and the surface 62 alternately to supply and return tubing pressure. The valve unit 94 comprises a piston 102 reciprocable in a bore 104 and a valve element 122 of smaller area than the piston connected thereto by a rod 126. Reciprocation of the piston 102 moves the element 122 to alternately expose the plunger surface 64 to the pressure in the supply tubing 96 or pressure in return tubing 98. The pump unit as shown, comprises a working valve 74 controlling the bore 48 of the rod 58 and standing valves 82, 86. In alternative constructions one or other of the standing valves may be omitted. On upward movement of the plunger, the valve 82 is unseated and oil is pushed up the production tubing 100. On downward movement of the plunger, the valve 74 is unseated and oil is transferred from beneath the lower plunger element 52 to above the upper plunger element 50. As shown in Fig. 3, the surface 64 is exposed to return tubing pressure through a duct 146, chamber 165 and a duct 166. When the plunger 46 reaches the upper end of its working stroke a groove 112 in the rod 58 interconnects ducts 114, 116 so that the space beneath the piston 102 is connected to the return tubing 98 through a check valve 120, duct 118, the groove 112 and ducts 116, 114 whence the valve begins to move downwardly at a first speed under the action of supply pressure acting on the upper surface of the element 122. Near the end of its downward movement the piston 102 covers a duet 148 whence fluid from beneath the piston is exhausted at a slower rate through ducts 138, 136, annular groove 134, a helical groove 132, annular recess 128 and a duct 130 so that it continues its downward movement at a slower second speed. Approaching the end of its downward stroke, a piston recess 140 communicates with a duct 142, increasing the rate at which fluid is exhausted so that the piston completes its downward movement at a third speed, faster than the second speed. During this time, the valve element 122 has cut communication between the surface 64 and the return tubing 98 and exposed the surface to supply pressure. The plunger 46 then commences its return stroke whence grooves 122a uncover the duct 146 at the commencement of the second piston speed. When the plunger 46 reaches the lower end of its return stroke, a groove 110 in the rod 58 interconnects the ducts 108, 116 so that the space beneath the piston 102 is connected to the supply tubing 96 through these ducts and groove, ducts 148, 152, a check valve 154 and a duct 138 so that the valve begins to move upwardly at a first speed until the duct 148 is covered. Fluid at a slower rate is then admitted to the space through ducts 162, 160, an annular piston groove 158, a helical groove 164 and ducts 136, 138, the piston continuing its downward movement at a slower second speed, until the near end of its downward movement, the piston recess 140 communicates with a branch 168 of the duct 162 to increase the rate at which fluid is admitted to the space. The piston finishing its movement at a slightly higher third speed. During this time the valve element 122 has moved upwardly to again expose the surface 64 to the pressure in the return tubing 98 so that the plunger 46 again moves upwardly. Movement commencing when the duct 148 is covered and " V " grooves in the element 122 uncover the duct 146. In addition, the valve unit 94, may include a speed governing action as well as the three-speed action. The upper ends of the production, supply and return tubings 100, 96, 98 are connected to a control device 246, Fig. 5, having lines 248, 250 connected to a pressure source and exhaust respectively and a production line 252. To instal the pump and valve units, closures 268, 270 at the upper ends of the tubings 100, 96 are removed and the units inserted in their respective tubings. To instal both units simultaneously the control device is set to connect the supply line 248 to both the supply and production tubing, fluid beneath the units being returned to the surface through the return tubing 98. If the pump unit is in place, fluid from beneath the valve unit may be returned through the valves 86, 74, 82 and the production tubing when the valve unit is installed. If the valve unit is installed before the pump unit, fluid from beneath the valve unit may return through either tubing 100 or tubing 98. To remove the valve unit without removal of the pump unit, the control device is set to close the upper end of the production tubing and the supply line 248 is connected to the return line 98 to direct pressure fluid to beneath the valve unit. To remove the pump unit without removing the valve unit the upper end of the supply tubing 96 is closed, instead of the upper end of the production tubing 100 and pressure fluid directed to beneath the pump unit to move it upwardly to insert a packer cup 356 into the production tubing so that pump unit and production tubing can both be removed.